plugins/meta/bandwith: traffic shaping plugin

Add chained plugin to add a tbf qdisc to shape ingress/egress traffic

plugins/meta/bandwidth/main.go

@@ -0,0 +1,218 @@
+// Copyright 2018 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package bandwidth
+
+import (
+	"crypto/sha1"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/containernetworking/cni/pkg/skel"
+	"github.com/containernetworking/cni/pkg/types"
+	"github.com/containernetworking/cni/pkg/types/current"
+	"github.com/containernetworking/cni/pkg/version"
+	"github.com/vishvananda/netlink"
+)
+
+type PluginConf struct {
+	types.NetConf
+	RuntimeConfig *struct{} `json:"runtimeConfig"`
+
+	// This is the previous result, when called in the context of a chained
+	// plugin. Because this plugin supports multiple versions, we'll have to
+	// parse this in two passes. If your plugin is not chained, this can be
+	// removed (though you may wish to error if a non-chainable plugin is
+	// chained.
+	// If you need to modify the result before returning it, you will need
+	// to actually convert it to a concrete versioned struct.
+	RawPrevResult *map[string]interface{} `json:"prevResult"`
+	PrevResult    *current.Result         `json:"-"`
+
+	// Add plugin-specifc flags here
+	IngressRate  int `json:"ingressRate"`  //Bandwidth rate in Kbps for traffic through container. 0 for no limit. If ingressRate is set, ingressBurst must also be set
+	IngressBurst int `json:"ingressBurst"` //Bandwidth burst in Kb for traffic through container. 0 for no limit. If ingressBurst is set, ingressRate must also be set
+
+	EgressRate  int `json:"egressRate"`  //Bandwidth rate in Kbps for traffic through container. 0 for no limit. If egressRate is set, egressBurst must also be set
+	EgressBurst int `json:"egressBurst"` //Bandwidth burst in Kb for traffic through container. 0 for no limit. If egressBurst is set, egressRate must also be set
+}
+
+// parseConfig parses the supplied configuration (and prevResult) from stdin.
+func parseConfig(stdin []byte) (*PluginConf, error) {
+	conf := PluginConf{}
+
+	if err := json.Unmarshal(stdin, &conf); err != nil {
+		return nil, fmt.Errorf("failed to parse network configuration: %v", err)
+	}
+
+	// Parse previous result. Remove this if your plugin is not chained.
+	if conf.RawPrevResult != nil {
+		resultBytes, err := json.Marshal(conf.RawPrevResult)
+		if err != nil {
+			return nil, fmt.Errorf("could not serialize prevResult: %v", err)
+		}
+		res, err := version.NewResult(conf.CNIVersion, resultBytes)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse prevResult: %v", err)
+		}
+		conf.RawPrevResult = nil
+		conf.PrevResult, err = current.NewResultFromResult(res)
+		if err != nil {
+			return nil, fmt.Errorf("could not convert result to current version: %v", err)
+		}
+	}
+	// End previous result parsing
+
+	err := validateRateAndBurst(conf.IngressRate, conf.IngressBurst)
+	if err != nil {
+		return nil, err
+	}
+	err = validateRateAndBurst(conf.EgressRate, conf.EgressBurst)
+	if err != nil {
+		return nil, err
+	}
+
+	return &conf, nil
+
+}
+
+func validateRateAndBurst(rate int, burst int) error {
+	switch {
+	case burst < 0 || rate < 0:
+		return fmt.Errorf("rate and burst must be a positive integer")
+	case burst == 0 && rate != 0:
+		return fmt.Errorf("if rate is set, burst must also be set")
+	case rate == 0 && burst != 0:
+		return fmt.Errorf("if burst is set, rate must also be set")
+	}
+
+	return nil
+}
+
+func getIfbDeviceName(networkName string, containerId string) (string, error) {
+	hash := sha1.New()
+	_, err := hash.Write([]byte(networkName + containerId))
+	if err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%x", hash.Sum(nil))[:4], nil
+}
+
+func getMTU(deviceName string) (int, error) {
+	link, err := netlink.LinkByName(deviceName)
+	if err != nil {
+		return -1, err
+	}
+
+	return link.Attrs().MTU, nil
+}
+
+func getHostInterface(interfaces []*current.Interface) (*current.Interface, error) {
+	for _, prevIface := range interfaces {
+		if prevIface.Sandbox != "" {
+			continue
+		}
+
+		return prevIface, nil
+	}
+
+	return nil, errors.New("no host interface found")
+}
+
+// cmdAdd is called for ADD requests
+func cmdAdd(args *skel.CmdArgs) error {
+	conf, err := parseConfig(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	//no traffic shaping was requested, so just no-op and quit
+	if conf.IngressRate == 0 && conf.IngressBurst == 0 && conf.EgressRate == 0 && conf.EgressBurst == 0 {
+		return types.PrintResult(conf.PrevResult, conf.CNIVersion)
+	}
+
+	if conf.PrevResult == nil {
+		return fmt.Errorf("must be called as chained plugin")
+	}
+
+	hostInterface, err := getHostInterface(conf.PrevResult.Interfaces)
+	if err != nil {
+		return err
+	}
+
+	if conf.IngressRate > 0 && conf.IngressBurst > 0 {
+		err = CreateIngressQdisc(conf.IngressRate, conf.IngressBurst, hostInterface.Name)
+		if err != nil {
+			return err
+		}
+	}
+
+	if conf.EgressRate > 0 && conf.EgressBurst > 0 {
+		mtu, err := getMTU(hostInterface.Name)
+		if err != nil {
+			return err
+		}
+
+		ifbDeviceName, err := getIfbDeviceName(conf.Name, args.ContainerID)
+		if err != nil {
+			return err
+		}
+
+		err = CreateIfb(ifbDeviceName, mtu)
+		if err != nil {
+			return err
+		}
+
+		ifbDevice, err := netlink.LinkByName(ifbDeviceName)
+		if err != nil {
+			return err
+		}
+
+		conf.PrevResult.Interfaces = append(conf.PrevResult.Interfaces, &current.Interface{
+			Name: ifbDeviceName,
+			Mac:  ifbDevice.Attrs().HardwareAddr.String(),
+		})
+		err = CreateEgressQdisc(conf.EgressRate, conf.EgressBurst, hostInterface.Name, ifbDeviceName)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Pass through the result for the next plugin
+	return types.PrintResult(conf.PrevResult, conf.CNIVersion)
+}
+
+// cmdDel is called for DELETE requests
+func cmdDel(args *skel.CmdArgs) error {
+	conf, err := parseConfig(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	ifbDeviceName, err := getIfbDeviceName(conf.Name, args.ContainerID)
+	if err != nil {
+		return err
+	}
+
+	if err := TeardownIfb(ifbDeviceName); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func main() {
+	skel.PluginMain(cmdAdd, cmdDel, version.PluginSupports("0.3.0", "0.3.1", version.Current()))
+}